Posting a location from the GeoGroups iPhone App is easy. Here is how it will appear on your Facebook wall.

How the post will appear on your facebook wall
Anyone viewing your wall can click/tap the post, which on the iPhone will open up a draggable map within the Facebook app, and a large full-screen map of the location and message on the desktop.

Tapping GeoGroups Facebook Wall Post Will Bring Up This Map
Example uses could be “Meet me here”, or “I Am Here”, without the burden of “check-ins” or any kind of geo-tagging whatsoever.
To send a location, tap the “send” button below the street-address on the home screen in the GeoGroups app. This will prompt to choose between posting to facebook or sending to a user or email address. Don’t worry, just choosing an option here won’t immediately send anything!
Choose “Post to Facebook”, and the send message screen will show up. Here you can edit the message and the location you want to send to your facebook wall. Tap “Send”. If this is the first time you are attempting this, the app will throw an error message about not having permission. Follow the prompt to go to the user options configuration page. Here, in the Facebook section, tap “Login” to go to the Facebook site. Here enter your facebook credentials, which will bring you back to the app.
Now, go back to the send message screen and tap send again. To see if it worked and how it looks, open the Facebook iPhone app to see your feed. You can always delete un-intended posts on your wall by swiping left on the post to see a delete button.
From now on, sending a location via the app requires only 3 taps, usually with no typing involved. 1) Tap Send Location 2) Choose Post To Facebook 3) Tap Send
As always, post feedback, comments or suggestions to the GeoGroups iPhone App Discussion Forum